Enhancing hydrogen production from steam electrolysis in molten hydroxides via selection of non-precious metal electrodes

Sher, Farooq; Al-Shara, Nawar K.; Iqbal, Sania Z.; Jahan, Zaib; Chen, George Z.

Abstract

© 2020 Hydrogen Energy Publications LLC There are still gaps in the field of reference electrode that is needed to assist electrolysis in high temperature electrolytes (e.g. molten hydroxides) for H2 gas production. This research aims to fill the gaps by preparing Ni/Ni(OH)2 reference electrode and more importantly testing its effectiveness against important performance factors including; ion conducting membrane (e.g. mullite tubes), internal electrolyte composition, working temperature and electrochemical control (e.g. potential scan rate). Then, this reference electrode was used to study the electrocatalytic activity various cheaper working electrode materials including; stainless steel (St.st), Ni, Mo and Ag in comparison with Pt by the means of chronoamperometry and voltammetry. The effect of introducing steam into electrolyte (eutectic mixture of NaOH and KOH) on the electrocatalytic activity of these working electrodes was also studied. It was observed that the potential of hydrogen evolution with different working electrodes followed an order as; Pt > Ni > St. st > Ag > Mo (positive to negative). The performance of each working electrode was confirmed through chronoamperometry for hydrogen evolution at a constant potential of −0.7 V. It was also found in cyclic voltammetry and confirmed by chronoamperometry that the introduction of steam was apparent as increasing the current density at cathodic limit for hydrogen evolution. This study could help to develop non-precious metal electrodes for the production of hydrogen fuel. In future, there will be a potential in the threshold concentration of steam for H2 gas production.

Citation

Sher, F., Al-Shara, N. K., Iqbal, S. Z., Jahan, Z., & Chen, G. Z. (2020). Enhancing hydrogen production from steam electrolysis in molten hydroxides via selection of non-precious metal electrodes. International Journal of Hydrogen Energy, 45(53), 28260-28271. https://doi.org/10.1016/j.ijhydene.2020.07.183

• Journal Article Type: Article
• Acceptance Date: Jul 20, 2020
• Online Publication Date: Aug 22, 2020
• Publication Date: Oct 30, 2020
• Deposit Date: Aug 24, 2020
• Publicly Available Date: Aug 23, 2021
• Journal: International Journal of Hydrogen Energy
• Print ISSN: 0360-3199
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 45
• Issue: 53
• Pages: 28260-28271
• DOI: https://doi.org/10.1016/j.ijhydene.2020.07.183
• Keywords: Fuel Technology; Renewable Energy, Sustainability and the Environment; Energy Engineering and Power Technology; Condensed Matter Physics
• Public URL: https://nottingham-repository.worktribe.com/output/4849733
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0360319920327932